1. PRISMS

2. Kelas : VIII-B
GROUP 5
GROUP 5

3. The Understanding of Prisms

6. BASE
FACE
TOP
FACE

7. BASE
FACE
TOP
FACE

8. BASE
FACE
TOP
FACE

13. 35 cm
A
B
C
D E
F
20CM

14. 35 cm
A
B
C
D E
F
20CM
a) FE2 =DE2 - DF2
= 352 -212
= 1225 – 441
= 784
=
FE = 28
Surface area = ( 2 x Area of base face) + (perimeter of base face x
height)
= (2 x ½ x 21 x 28) + ((21+28+35) x 20)
= (2 x 294 ) + (84 x 20)
= 588 + 1680
= 2268 (D)

15. b) Volume of the prism
= area of base face x height
=( ½ x 21 x 28) x 20
= ( ½ x 588) x 20
= 294 x 20
= 5880 (A)
B
35 cm
A C
D E
F
20CM

16. 2. Find the surface area !
30 cm

17. = 152 – 392
= 1521 – 225
= 1296
=
= 36
Surface area = ( 2 x Area of base face) + (perimeter of
base face x height)
= (2 x ½ x 30 x 36 ) + ((30+39+39) x 36)
= (30 x 36) + (108 x 36)
= 1080 + 3888
= 4968 cm
30 cm
36cm

18. 3. Length, width, and height a rectangular prism
are 3 : 2 : 1. If the volume of prism is 750 cm3.
So, the surface area of the prism is . . . .

19. Given :
• P = 3n t = n
• l = 2n V = 750 cm3
Answer :
Vprism = Area of base face x height
= (P x l ) x t
750 = (3n x 2n) x n
750 = 6n2 x n
750 = 6n3
= n3
125 = n3
= n
5 = n